N-lines in the luminescence spectra of Cr3+ -doped spinels (I) identification of N-lines

A series of novel temperature-sensitive phosphors LiAl5(1−x)O8: xCr3+ (x = 0.001–0.012) are synthesized by combustion method. The phosphors can be efficiently excited by the whole wavelength range of the visible light, producing strong deepred emission, which can be assigned to the 2E → 4A2 transition. The intensity, peak wavelength and decay lifetime of the emission are measured to vary strongly with temperature for all the samples. Especially, the decay lifetime change dramatically from 4.31 ms to 0.38 ms from 200 K to 600 K for the sample with x = 0.002, which give a highest temperature sensitivity of −0.015 ms K−1 at 400 K and a maximal relative sensitivity of 0.83% K−1 at 447 K. These results show that LiAl5O8:Cr3+ is promising for optical thermometry.

Luminescent properties of chromium(III)-doped lithium aluminate for temperature sensing

Luminescence of FE3+ in single crystals of LiAl5O8

Investigations of the optical and EPR properties of LiGa5O8:Cr3+ phosphor

Phosphors based on transition metal-activated gallates, particularly Cr 3+ - and Ni 2+ -activated zinc germanium gallates, are disclosed herein. In some embodiments such phosphors can exhibit persistent infrared phosphorescence for as long as 400 hours. Such phosphors can be used, for example, as components of a luminescent paint.

T. Abritta

Papers

The optical properties of Cr3+ in LiAl5O8 and LiGa5O8